TRANSMITTER AND METHOD FOR TRANSMITTING DATA BLOCK IN WIRELESS COMMUNICATION SYSTEM

Description

[Technical Field]

[0001] The present invention relates to wireless communication, and more particularly, to a method of transmitting a data block in a wireless communication system, and a transmitter.

[Background Art]

[0002] Recently, various wireless communication technologies are under development in accordance with the advancement of information communication technology. Among them, a wireless local area network (WLAN) is a technique allowing mobile terminals such as personal digital assistants (PDAs), lap top computers, portable multimedia players (PMPs), and the like, to wirelessly access the Internet at homes, in offices, or in a particular service providing area, based on a radio frequency technology.

[0003] As a technology specification that has been relatively recently legislated in order to overcome a limitation in a communication speed that has been pointed out as a weak point in the WLAN, there is the IEEE (Institute of Electrical and Electronics Engineers) 802.11n. An object of the IEEE 802.11n is to increase a speed and reliability of a wireless network and extend an operating distance of the wireless network. More specifically, the IEEE 802.1 In is based on multiple inputs and multiple outputs (MIMO) technology in which multiple antennas are used at both of a transmitting end and a receiving end in order to support a high throughput (HT) having a maximum data processing speed of 540 Mbps or more, minimize a transmission error, and optimize a data speed. Further, in this specification, a coding scheme of transmitting several overlapped duplicates may be used in order to increase data reliability, and an orthogonal frequency division multiplexing (OFDM) scheme may also be used in order to increase a speed.

[0004] In the wireless communication system, codewords are generally interleaved over the entire frequency band in order to obtain a frequency diversity gain and maximize an interleaving effect. When a size of a used frequency band increases, a coding gain and a diversity gain are obtained by increasing a codeword and an interleaver to the size of the frequency band.

[0005] However, when the size of the interleaver is increased in accordance with an increase in size of the frequency band, a burden on changing an existing structure and complexity may increase.

[0006] BJORN A. BJERKE (QUALCOMM): "Lb84 Replacement Text Data Interleaver; 11-06-0592-00-000n-lb84-replacement-text-data-interleaver", IEEE DRAFT; 11-06-0592-00-000N-LB84-REPLACEMENT-TEXT-DATA-INTERLEAVER, IEEE-SA MENTOR, PISCATAWAY, NJ USA, vol. 802.11 n, 28 April 2006, pages 1-4, concerns a technique relating to a data interleaver for 802.11 n Wireless LANs, describing a stream parser which determines the number of bits assigned to a single axis in a constellation point in a spatial stream and assigns consecutive blocks of bits to different spatial streams in a round robin fashion

[0007] ROBERT STACEY (INTEL): "Proposed Specification Framework for TGac ; 11-09-0992-16-00ac-proposed-specification- framework-for-tgac", IEEE DRAFT; 11-09-0992-16-00AC-PROPOSED-SPECIFICATION- FRAMEWORK-FOR-TGAC, IEEE-SA MENTOR, PISCATAWAY, NJ USA, vol. 802.11ac, no. 16, 9 November 2010, pages 1-35, concerns techniques for use in 802.11 n Wireless LANs.

[0008] WO 2012/051319 A1 discloses a communication device comprising a network interface which includes at least a first transmit flow unit, and a second transmit flow unit. The network interface is configured to generate, using the first transmit flow unit and when in a composite channel transmit mode, a first set of OFDM tones, and generate, using the second transmit flow unit and when in the composite channel transmit mode, a second set of OFDM tones. Further, the network is configured to generate, when in the composite channel transmit mode, a composite channel OFDM symbol comprising the first and second sets of OFDM tones. The composite channel OFDM symbol includes lower-edge and upper-edge guard tones, with at least one of the number of lower-edge guard tones being greater than a first number of lower-edge guard tones used in a first transmit mode different than the composite channel transmit mode and greater than a second number of lower-edge guard tones used in a second transmit mode different than the composite channel transmit mode, and the number of upper-edge guard tones being greater than a first number of upper-edge guard tones used in the first transmit mode and greater than a second number of upper-edge guard tones used in the second transmit mode.

[0009] ROBERT STACEY (INTEL): "Proposed Specification Framework for TGac ; 11-09-0992-12-00ac-proposed-specification-framework-for-tgac", IEEE DRAFT; 11-09-0992-12-00AC-PROPOSED-SPECIFICATION- FRAMEWORK-FOR-TGAC, IEEE-SA MENTOR, PISCATAWAY, NJ USA, vol. 802.11ac, no. 12, 15 July 2010, pages 1-18, concerns techniques for use in 802.11 n Wireless LANs.

[0010] YOUHAN KIM (ATHEROS): "160 Mhz Tranmission Flow ; 11-10-1063-00-00ac-160-mhz-tranmission-flow", IEEE DRAFT; 11-10-1063-00-00AC-160-MHZ-TRANMISSION-FLOW, IEEE-SA MENTOR, PISCATAWAY, NJ USA, vol. 802.11ac, 13 September 2010 (2010-09-13), pages 1-19, concerns techniques for 160 MHz transmission flow in 802.11 Wireless LANs.

[Disclosure]

[Technical Problem]

[0011] The present invention provides a method of transmitting a data block capable of supporting a broadband in a wireless local area network system, and a transmitter.

[Technical Solution]

[0012] The present invention is defined in the independent claims. The dependent claims define further embodiments of the present invention.

[0013] In an aspect, a method of transmitting a data block in a wireless communication system is provided. The method includes determining a number of bits assigned to a single axis of a signal constellation, s, and a number of encoders, N_ES, encoding and parsing information bits to generate a coded block of N_CBPSS bits per spatial stream, parsing the coded block to generate a plurality of frequency subblocks based on s and N_ES, and transmitting the plurality of frequency subblocks to a receiver.

where NBPSCS is the number of coded bits per subcarrier per spatial stream.

[0014] The step of encoding the information bits may include encoding the information bits by using NES forward error correction (FEC) encoders, and rearranging the encoded information bits to generate the coded block of NCBPSS bits based on s and NES.

[0015] The signal constellation may be used for at least one of Binary phase shift keying (BPSK), Quadrature phase shift keying (QPSK), 6-Quadrature amplitude modulation (QAM), 64-QAM and 256-QAM.

[0016] The plurality of frequency subblocks may correspond to a plurality of frequency bands respectively.

[0017] Each frequency band may have a bandwidth of 80MHz.

[0018] A number of the plurality of frequency subblocks may be two.

[0019] The coded block may be parsed by using a round robin scheme to generate the plurality of frequency subblocks.

[0020] In another aspect, a transmitter of transmitting a data block in a wireless communication system is provided. The transmitter includes a coding unit configured to determine a number of bits assigned to a single axis of a signal constellation, s, and a number of encoders, N_ES and encode and parse information bits to generate a coded block of N_CBPSS bits per spatial stream, a parsing unit configured to parse the coded block to generate a plurality of frequency subblocks based on s and N_ES, and a transmission unit configured to transmit the plurality of subblocks to a receiver.

[0021] In still another aspect, a method of transmitting a data block in a wireless communication system is provided. The method includes determining a number of bits assigned to a single axis of a signal constellation, s, and a number of encoders, N_ES, generating a coded block, parsing the coded block to generate a plurality of frequency subblocks in unit of sN_ES bits, and transmitting the plurality of frequency subblocks to a receiver.

[Advantageous Effects]

[0022] It is possible to prevent decoding performance of a receiver from being deteriorated by allowing contiguous bits of an encoding block not to continuously have the same reliability on a signal constellation.

[Description of Drawings]

[0023] 

FIG. 1 is a diagram showing an architecture of the IEEE 802. 11.

FIG. 2 is a block diagram showing an example of a physical layer convergence procedure (PLCP) protocol data unit (PPDU) format.

FIG. 3 is a block diagram showing an example of a transmitter in which an exemplary embodiment of the present invention is implemented in contiguous bands.

FIG. 4 is a block diagram showing an example of a transmitter in which the exemplary embodiment of the present invention is implemented in non-contiguous bands.

FIG. 5 is a diagram showing an example of segment parsing.

FIG. 6 is an example of showing an example in which the segment parsing of FIG. 5 is used.

FIG. 7 is an example showing another example in which the segment parsing of FIG. 5 is used.

FIG. 8 is a diagram showing an example of segment parsing according to the exemplary embodiment of the present invention.

FIG. 9 is a diagram showing another example of segment parsing according to the exemplary embodiment of the present invention.

FIG 10 is a diagram showing segment parsing according to the exemplary embodiment of the present invention.

FIG. 11 is a diagram showing segment parsing according to another exemplary embodiment of the present invention.

FIGS. 12 to 14 are diagrams showing simulation results.

FIG. 15 is a flow chart showing a method of transmitting data according to the exemplary embodiment of the present invention.

FIG. 16 is a flow chart showing a method of transmitting data according to another exemplary embodiment of the present invention.

FIG. 17 is a block diagram showing a transmitter in which the exemplary embodiment of the present invention is implemented.

[Mode for Invention]

[0024] A wireless local area network (WLAN) system in which an exemplary embodiment of the present invention is implemented includes at least one basic service set (BSS). The BSS is a set of successfully synchronized stations (STA) in order to perform communication therebetween. The BSS may be divided into an independent BSS (IBSS) and an infrastructure BSS.

[0025] The BSS may include at least one STA and access point (AP). The STA may be an AP or non-AP STA. The AP is a functional medium connecting the STAs in the BSS to each other through a wireless medium. The AP may be called other names such as a centralized controller, a base station (BS), a scheduler, and the like.

[0026] FIG. 1 is a diagram showing an architecture of the IEEE 802. 11.

[0027] The wireless-medium physical layer (PHY) architecture of the IEEE 802.11 includes a PHY layer management entity (PLME) layer, that is, a physical layer convergence procedure (PLCP) sub-layer 110, a physical medium dependent (PMD) sub-layer 110.

[0028] The PLME provides a management function of the PHY in cooperation with a medium access control (MAC) layer management entity (MLME).

[0029] The PLCP sub-layer 110 transfers an MAC protocol data unit (MPDU) received from the MAC sub-layer 120 to a PMD sub-layer 100 or transfers a frame coming from the PMD sub-layer 100 to the MAC sub-layer 120 according to instruction of the MAC layer, between the MAC sub-layer 120 and the PMD sub-layer 100.

[0030] The PMD sub-layer 100, which is a lower layer of the PLCP, may allow a PHY entity to be transmitted and received between two STAs through a wireless medium.

[0031] The MPDU transferred from the MAC sub-layer 120 is called a physical service data unit (PSDU) in the PLCP sub-layer 110. The MPDU is similar to the PSDU. However, when an aggregated MPDU (A-MPDU) in which a plurality of MPDUs are aggregated is transferred, individual MPDUs and PSDUs may be different.

[0032] The PLCP sub-layer 110 adds an additional field including information required by a physical layer transceiver to the PSDU during a process of receiving the PSDU from the MAC sub-layer 120 and transferring the PSDU to the PMD sub-layer 100. Here, the field added to the MPDU may be a PLCP preamble, a PLCP header, tail bits required on a data field, or the like. The PLCP preamble serves to allow a receiver to prepare a synchronization function and antenna diversity before the PSDU is transmitted. The PLCP header includes a field including information on a frame.

[0033] The PLCP sub-layer 110 adds the above-mentioned field to the PSDU to generate a PLCP protocol data unit (PPDU) and transmit the PPDU to a receiving station through the PMD sub-layer. The receiving station receives the PPDU and obtains information required for recovering data from the PLCP preamble and the PLCP header to recover the data.

[0034] FIG. 2 is a block diagram showing an example of a physical layer convergence procedure (PLCP) protocol data unit (PPDU) format.

[0035] The PPDU 600 may include a legacy-short training field (L-STF) 610, a legacy-long training field (L-LTF) 620, a legacy-signal (L-SIG) field 630, a very high throughput (VHT)-SIGA field 640, a VHT-STF 650, a VHT-LTF 660, a VHT-SIGB 670, and a data field 680.

[0036] The L-STF 610 is used for frame timing acquisition, automatic gain control (AGC), coarse frequency acquisition, or the like.

[0037] The L-LTF 620 is used for channel estimation for demodulation of the L-SIG field 630 and the VHT-SIGA field 640.

[0038] The L-SIG field 630 includes control information on a transmission time of the PPDU.

[0039] The VHT-SIGA field 640 includes common information required for the STAs supporting the MIMO transmission to receive a spatial stream. The VHT-SIGA field 640 includes information on the spatial streams for each STA, channel bandwidth information, a group identifier, information on an STA to which each ground identifier is allocated, a short guard interval (GI), beamforming information (including whether the MIMO is SU-MIMO or MU-MIMO).

[0040] The VHT-STF 650 is used to improve performance of AGC estimation in the MIMO transmission.

[0041] The VHT-LTE 660 is used for each STA to estimate MIMO channels.

[0042] The VHT-SIGB field 670 includes individual control information on each STA. The VHT-SIGB field 670 includes information on a modulation and coding scheme (MCS). A size of the VHT-SIGB field 670 may be changed according to a type of MIMO transmission (MU-MIMO or SU-MIMO) and a bandwidth of a channel used for transmission the PPDU.

[0043] The data field 680 includes the PSDU transferred from the MAC layer, a service field, tail bits, and pad bits if needed.

[0044] In order to support a higher data rate, the WLAN system may support various bandwidths. For example, the bandwidth supported by the WLAN system may include at least any one of 20MHz, 40Hz, 80MHz, and 160MHz. In addition, since continuous bandwidths may not be always used, non-contiguous bands may be used. For example, a bandwidth of 160 MHz is supported using two non-contiguous 80 MHz bands (represented by 80+80 MHz).

[0045] Hereinafter, a contiguous 160 MHz band and a non-contiguous 80+80 MHz band will be described by way of example. However, sizes or the number of bandwidths are not limited.

[0046] The WLAN system may support the MU-MIMO and/or the SU-MIMO. Hereinafter, the SU-MIMO will be described by way of example. However, it may be easily appreciated by those skilled in the art that this description may also be to the MU-MIMO.

[0047] FIG. 3 is a block diagram showing an example of a transmitter in which an exemplary embodiment of the present invention is implemented in contiguous bands.

[0048] A data unit is encoded by at least one forward error correction (FEC) encoder (S710). The data unit includes PHY pad bits added to the PSDU and scrambled information bits. The data unit may be divided into bit sequences having a specific bit size by an encoder parser, and each of the bit sequences may be input to each FEC encoder.

[0049] An encoding scheme may be a binary convolution code (BCC). However, a disclosed encoding scheme is only an example, and the scope of the present invention may be applied to a well-known encoding scheme such as a low-density parity-check (LDPC), a turbo code, or the like, by those skilled in the art.

[0050] The encoded data units are rearranged into NSS spatial blocks by a stream parser (S720). N_SS indicates the number of spatial streams.

[0051] Output bits of each stream parser are divided into two frequency subblocks (S730). One frequency subblock may correspond to a bandwidth of 80 MHz.

[0052] Each of the two frequency subblocks is independently interleaved by a BCC interleaver (S740). The interleaver may have a size corresponding to 20 MHz, 40 MHz, and 80 MHz. Since one frequency subblock corresponds to a 80 MHz band, the frequency subblocks may be interleaved by an interleaver corresponding to 80 MHz.

[0053] Each of the interleaved frequency subblocks is independently mapped onto a signal constellation by a constellation mapper (S750). The signal constellation may correspond to various modulation schemes such as binary phase shift keying (BPSK), quadrature phase-shift keying (QPSK), 16-quadrature amplitude modulation (QAM), 64-QAM, or 256-QAM, but is not limited thereto.

[0054] The mapped subblocks are spatially mapped using space-time block coding (STBC) and cyclic shift delay (CSD) (S760).

[0055] Two spatially mapped subblocks are subjected to inverse discrete Fourier transform (IDFT) and then transmitted (S770).

[0056] FIG. 4 is a block diagram showing an example of a transmitter in which the exemplary embodiment of the present invention is implemented in non-contiguous bands.

[0057] In comparison with the transmitter of FIG. 3, each of the two frequency subblocks is independently subjected to the IDFT. Since each of the frequency subblocks corresponds to the 80 MHz band and the bandwidth of 80 MHz is non-contiguous, each of the two frequency subblocks is independently subjected to the IDFT.

[0058] The segment parser parses the encoded data unit into a plurality of frequency subblocks. This is to support a wider bandwidth without increasing a size of the BCC interleaver.

[0059] For example, assume that an existing BCC interleaver supports a bandwidth up to 80 MHz. In order to support a bandwidth of 160 MHz, the BCC interleaver cannot but be changed so as to support 160 MHz. However, the data stream is parsed into the subblocks having a size of a frequency bandwidth supported by the BCC interleaver using the segment parser. Therefore, it is possible to support a wider bandwidth and obtain a frequency diversity gain, without changing a size of the interleaver.

[0060] Hereinafter, the following parameters will be defined.

N_CBPS: number of coded bits per symbol

N_CBPSS: number of coded bits per symbol per spatial stream

N_BPSC: number of coded bits per subcarrier over all spatial streams)

N_BPSCS: number of coded bits per subcarrier per spatial stream)

Nss: number of spatial streams

N_ES: number of encoders for data field. Here, it is assumed that the number of encoders is the same as that of codewords.

R: code rate

[0061] FIG. 5 is a diagram showing an example of segment parsing. The existing suggested simplest segment parsing is to allocate even bits to a first subblock and allocate odd bits to a second subblock for each spatial stream.

[0062] FIG 6 is an example of showing an example in which the segment parsing of FIG. 5 is used. In the case of FIG. 6, a modulation scheme is 64-QAM, N_ES is 4, N_SS is 6, R is 6/5, and a bandwidth is 80 MHz.

[0063] The number of bits corresponding to a Q-axis (or an I-axis) of a 64-QAM signal constellation is 3. Therefore, an output of an encoder is allocated 3-bit by 3-bit in a round robin scheme for each spatial stream. Each spatial stream is parsed by the stream parser to generate subblocks.

[0064] The generated subblocks are interleaved by an interleaver. Interleaver input bits are sequentially filled in 26 rows, 3j, 3j+1, and 3j+2 rows of a 3i-th row are mapped to a signal constellation as they are, and 3j, 3j+1, and 3j+2 rows of a 3i+1-th row are cyclically shifted downwardly by a single column and then mapped to the signal constellation. 3j, 3j+1, and 3j+2 rows of a 3i+2-th row are cyclic-shifted downwardly by two columns and then mapped to the signal constellation.

[0065] Under the above-mentioned conditions, continuous bits of a codeword are mapped to positions having different reliabilities on the signal constellation.

[0066] FIG 7 is an example showing another example in which the segment parsing of FIG. 5 is used. In the case of FIG 7, a modulation scheme is 64-QAM, N_ES is 1 or 2, N_SS is 1, R is 6/5, and a bandwidth is 160MHz. Unlike the example of FIG. 6, under these conditions, the continuous bits of the codeword are continuously mapped to positions having the same reliability on the signal constellation.

[0067] When the bits of the codeword continuously have the same reliability on the signal constellation, decoding performance of a receiver may be significantly deteriorated. The reason is that when a channel state is deteriorated in the reliability, an error may occur.

[0068] Therefore, the exemplary embodiment of the present invention suggests segment parsing allowing the bits of the codeword not to continuously have the same reliability on the signal constellation.

[0069] In the suggested segment parsing, the number of encoders and the number of bits allocated to one axis of the signal constellation are considered.

[0070] The number s of bits allocated to one axis of the signal constellation is considered as follows:

[0071] For example, when a modulation scheme is BPSK or QPSK, s is 1, when a modulation scheme is 16-QAM, s is 2, when a modulation scheme is 64-QAM, s is 4, and when a modulation scheme is 256-QAM, s is 4.

[0072] FIG. 8 is a diagram showing an example of segment parsing according to the exemplary embodiment of the present invention. FIG. 8 shows an example in which bits are allocated to two frequency subblocks in an s unit for each of spatial streams according to each modulation scheme.

[0073] FIG. 9 is a diagram showing another example of segment parsing according to the exemplary embodiment of the present invention. In this example, outputs of each of encoders are bounded. That is, the outputs of the encoders are parsed in an sN_ES unit for each of spatial streams.

[0074] Contiguous bits of a codeword may be mapped so as to have different reliabilities on a signal constellation.

[0075] The example of FIG. 9 is mathematically shown as follows.

[0076] Output bits of each of spatial stream parsers are divided into blocks of N_CBPSS bits. Each of the blocks is parsed into two frequency subblocks of N_CBPSS/2 bits as shown by the following Equation 2:

where

└ z ┘ is the largest integer less than or equal to z,

z mod t is the remainder resulting from the division of integer z by integer t,

x_m is the m-th bit of a block of N_CBPSS bits (m=0,..., N_CBPSS-1),

l is the subblock index, and l=0, 1,

y_k,l is the k-th bit of a subblock l.

[0077] Meanwhile, when the number of bits of a coded block (that is, the number of bits of an i-th spatial block) is not a multiple of 2sN_ES, residue bits that are not allocated to the frequency subblocks may be present. That is, when the number of bits of the coded block is not divided by 2sN_ES, a method of allocating the residue bits is problematic. Typically, the following cases in a bandwidth of 160 MHz are problematic.

(1) 64-QAM, R=2/3, N_SS=5, N_ES=5

(2) 64-QAM, R=2/3, N_SS=7, N_ES=7

(3) 64-QAM, R=3/4, N_SS=5, N_ES=5

(4) 64-QAM, R=3/4, N_SS=7, N_ES=7

[0078] FIG. 10 is a diagram showing segment parsing according to the exemplary embodiment of the present invention.

[0079] Bits up to └ N_CBPSS/(2sN_ES) ┘ sN_ES are parsed as shown by Equation 2. Here, 2sQ (Q=(N_CBPSS mod 2sN_ES)/(2s)) residue bits that are not parsed remain. Then, the residue bits are divided by subsets of s bits. Each of the subsets is allocated to different subblocks in the round robin scheme. A first s bit is allocated to a first subblock (l=0). That is, a bundle of s bits is sequentially allocated to first and second subblocks.

[0080] That is, when N_CBPSS is not divided by 2sN_ES, each block is parsed into two frequency subblocks of N_CBPSS/2 bits as shown by the following Equation 3:

[0081] Equation 3 additionally shows allocation of the residue bits in Equation 2.

[0082] FIG. 11 is a diagram showing segment parsing according to another exemplary embodiment of the present invention.

[0083] Bits up to └ N_CBPSS/(2sN_ES) ┘ sN_ES are parsed as shown by Equation 2. Then, the residue bits are divided by subsets of 2 bits. Each of the subsets is allocated to different subblocks in the round robin scheme.

[0084] FIGS. 12 to 14 are diagrams showing simulation results. FIG 12 shows simulation results in a case in which N_SS is 3, a modulation scheme is 16-QAM, and R is 1/2, FIG. 13 shows simulation results in a case in which N_SS is 3, a modulation scheme is 16-QAM, and R and 3/4, and FIG. 14 shows simulation results in a case in which N_SS is 3, a modulation scheme is 256-QAM, and R is3/4. 'Nseg=1' indicates that a single interleaver is used over a bandwidth of 60 MHz without segment parsing. 'Nseg=2 and parser=0' indicate that the existing segment parsing of FIG 5 is used. 'Nseg=2 and parser=1' indicate that the suggested segment parsing of FIG. 10 is used.

[0085] It is shown that a packet error rate (PER) is increased in the case of the existing segment parsing as compared to the case in which the segment parsing is not performed; however, a PER is not almost increased in the case of the suggested segment parsing as compared to the case in which the segment parsing is not performed.

[0086] FIG. 15 is a flow chart showing a method of transmitting data according to the exemplary embodiment of the present invention.

[0087] Information bits are encoded to generate a coded block (S910). The encoding may include spatial mapping by a stream parser as well as FEC encoding such as BCC or LDPC. The number of bits of a coded block (per a spatial stream) is N_CBPSS.

[0088] The stream parser may perform parsing based on s. Output bits of an FEC encoder are rearranged into N_SS spatial blocks of N_CBPSS bits. Contiguous blocks of s bits may be allocated to different spatial streams in the round robin scheme.

[0089] Segment parsing is performed in a first segment unit (S920). The first segment unit may have a value of sN_ES. Each of the encoded blocks may be parsed into M frequency subblocks of N_CBPSS/M bits. The subblock may correspond to a bandwidth corresponding to a size of an interleaver.

[0090] When M is 2, the encoded block may be parsed to be divided into two subblocks as shown by Equation 2.

[0091] It is determined whether or not residue bits are present (S930).

[0092] When N_CBPSS is not divided in an M×first segment unit (that is, when N_CBPSS is not a multiple of the M×first segment unit), residue bits may be parsed in M frequency subblocks in a second segment unit (S940). The first segment unit N_ES is times larger than the second segment unit, which may have a value of s. When M is 2, the encoded block may be parsed to be divided into two subblocks as shown by Equation 3.

[0093] Each of the subblocks is transmitted to a receiver (S950). The parsed subblocks are independently interleaved by the interleaver, mapped onto a signal constellation, and then transmitted.

[0094] FIG. 16 is a flow chart showing a method of transmitting data according to another exemplary embodiment of the present invention.

[0095] Information bits are encoded to generate a coded block (S1010). The encoding may include spatial mapping by a stream parser as well as FEC encoding such as BCC or LDPC. The number of bits of a coded block (per a spatial stream) is NCBPSS.

[0096] The stream parser may perform parsing based on s. Output bits of an FEC encoder are rearranged into N_CBPSS bits of N_SS spatial blocks. Contiguous blocks of s bits may be allocated to different spatial streams in the round robin scheme.

[0097] Whether or not N_CBPSS, which is a size of the coded block, is divided by a reference value is determined (S1020). The reference value may be an Mxfirst segment unit.

[0098] When N_CBPSS is divided by the M×first segment unit, segment parsing is performed in a first segment unit (S1030). The first segment unit may have a value of sN_ES. Each of the encoded blocks may be parsed into N_CBPSS/M bits of M frequency subblocks. The subblock may correspond to a bandwidth corresponding to a size of an interleaver. When M is 2, the encoded block may be parsed to be divided into two subblocks as shown by Equation 2.

[0099] When N_CBPSS is not divided by the M×first segment unit, residue bits may be parsed into M frequency subblocks in first and second segment units (S1040). The first segment unit N_ES is times larger than the second segment unit. The first segment unit may have a value of sN_ES, and the second segement unit may have a value of s. The segment parsing is first performed in the first segment unit, and then performed in the second segment unit with respect to the residue bits. When M is 2, the encoded block may be parsed to be divided into two subblocks as shown by Equation 3.

[0100] Each of the subblocks is transmitted to a receiver (S1050). The parsed subblocks are independently interleaved by the interleaver, mapped onto a signal constellation, and then transmitted.

[0101] FIG. 17 is a block diagram showing a transmitter in which the exemplary embodiment of the present invention is implemented. The exemplary embodiments of FIGS. 15 and 16 may be implemented by the transmitter.

[0102] The transmitter 1000 includes a coding unit 1010, a parsing unit 1020, and a transmission unit 1030. The coding unit 1010 may implement functions of the FEC encoding and the stream parser of FIGS. 3 and 4. The parsing unit 1020 may implement a function of the segment parser of FIGS. 3 and 4. The transmission unit 1030 may implement functions of the interleaver and the constellation mapper of FIGS. 3 and 4.

[0103] The coding unit 1010 generates an encoded block. The parsing unit 1020 parses the encoded block into a plurality of frequency subblocks. The segment parsing Equation 2 or Equation 3 may be implemented by the parsing unit 1020. The transmitting unit 1030 transmits the subblocks to a receiver.

[0104] The coding unit 1010, the parsing unit 1020 and the transmission unit 1030 may be implemented by one or more processors. The processor may include application-specific integrated circuit (ASIC), other chipset, logic circuit and/or data processing device. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and/or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in memory and executed by processor. The memory can be implemented within the processor or external to the processor in which case those can be communicatively coupled to the processor via various means as is known in the art.

[0105] In view of the exemplary systems described herein, methodologies that may be implemented in accordance with the disclosed subject matter have been described with reference to several flow diagrams. While for purposed of simplicity, the methodologies are shown and described as a series of steps or blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the order of the steps or blocks, as some steps may occur in different orders or concurrently with other steps from what is depicted and described herein. Moreover, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope of the present disclosure.

Claims

1. A method of transmitting a data block in a wireless communication system, comprising:

determining a number of bits assigned to a single axis of a signal constellation, s, and a number of encoders, N_ES;

encoding and parsing information bits to generate (S910) a coded block of N_CBPSS bits per spatial stream;

parsing the coded block to generate a plurality of frequency subblocks based on s (S940) and N_ES (S920);

interleaving each of two frequency subblocks independently by using an interleaver having a size corresponding to a bandwidth of a frequency band corresponding to one of the plurality of frequency subblocks (S950); and

transmitting (S950) the plurality of interleaved frequency subblocks to a receiver.

2. The method of claim 1, wherein

where N_BPSCS is the number of coded bits per subcarrier per spatial stream.

3. The method of claim 2, wherein the step of encoding the information bits includes:

encoding the information bits by using N_ES forward error correction (FEC) encoders; and

rearranging the encoded information bits to generate the coded block of N_CBPSS bits based on s.

4. The method of claim 2, wherein the signal constellation is used for at least one of Binary phase shift keying (BPSK), Quadrature phase shift keying (QPSK), 16-Quadrature amplitude modulation (QAM), 64-QAM and 256-QAM.

5. The method of claim 2, wherein the plurality of frequency subblocks correspond to a plurality of frequency bands respectively.

6. The method of claim 5, wherein each frequency band has a bandwidth of 80MHz.

7. The method of claim 6, wherein a number of the plurality of frequency subblocks is two.

8. The method of claim 1, wherein the coded block is parsed by using a round robin scheme to generate the plurality of frequency subblocks.

9. A transmitter (1000) of transmitting a data block in a wireless communication system, comprising:

a coding unit (1010) configured to determine a number of bits assigned to a single axis of a signal constellation, s, and a number of encoders, N_ES and encode and parse information bits to generate a coded block of N_CBPSS bit per spatial stream;

a parsing unit (1020) configured to parse the coded block to generate a plurality of frequency subblocks based on s and N_ES; and

a transmission unit (1030) configured to interleave each of two frequency subblocks independently by using an interleaver having a size corresponding to a bandwidth of a frequency band corresponding to one of the plurality of frequency subblocks and transmit the plurality of interleaved frequency subblocks to a receiver.

10. The transmitter of claim 9, wherein

where N_BPSCS is the number of coded bits per subcarrier per spatial stream.

11. The transmitter of claim 10, wherein the coding unit configured to encode the information bits by:

encoding the information bits by using N_ES forward error correction (FEC) encoders; and

rearranging the encoded information bits to generate the coded block of N_CBPSS bits based on s.

12. The transmitter of claim 10, wherein the signal constellation is used for at least one of Binary phase shift keying (BPSK), Quadrature phase shift keying (QPSK), 16-Quadrature amplitude modulation (QAM), 64-QAM and 256-QAM.

13. The transmitter of claim 10, wherein the plurality of frequency subblocks correspond to a plurality of frequency bands respectively.

14. The transmitter of claim 13, wherein each frequency band has a bandwidth of 80MHz.

15. The transmitter of claim 14, wherein a number of the plurality of frequency subblocks is two.

Ansprüche

1. Verfahren zum Senden eines Datenblocks in einem drahtlosen Kommunikationssystem, umfassend:

Bestimmen einer Anzahl von Bits, die einer einzelnen Achse einer Signalkonstellation s zugeteilt sind, und einer Anzahl von Codierern N_ES;

Codieren und Parsen von Informationsbits, um einen codierten Block von N_CBPSS Bits pro räumlichem Strom zu erzeugen (S910);

Parsen des codierten Blocks, um eine Vielzahl von Frequenz-Unterblöcken zu erzeugen, basierend auf s (S940) und N_ES (S920);

unabhängiges Anwenden von Interleaving auf jeden von zwei Frequenz-Unterblöcken durch Verwenden eines Interleavers mit einer Größe entsprechend einer Bandbreite eines Frequenzbands entsprechend einem der Vielzahl von Frequenz-Unterblöcken (S950); und

Senden (S950) der Vielzahl von einem Interleaving unterzogenen Frequenz-Unterblöcken zu einem Empfänger.

2. Verfahren nach Anspruch 1, wobei

gilt, wobei N_BPSCS die Anzahl von codierten Bits pro Hilfsträger pro räumlichem Strom ist.

3. Verfahren nach Anspruch 2, wobei der Schritt zum Codieren der Informationsbits folgendes enthält:

Codieren der Informationsbits durch Verwenden von N_ES Vorwärtsfehlerkorrektur-(FEC-)Codierern; und

neu Anordnen der codierten Informationsbits, um den codierten Block von N_CBPSS Bits zu erzeugen, basierend auf s.

4. Verfahren nach Anspruch 2, wobei die Signalkonstellation für wenigstens eines von binärer Phasenumtastung (BPSK), Quadraturphasenumtastung.(QPSK), 16-Quadraturamplitudenmodulation (QAM), 64-QAM und 256-QAM verwendet wird.

5. Verfahren nach Anspruch 2, wobei die Vielzahl von Frequenz-Unterblöcken jeweils einer Vielzahl von Frequenzbändern entspricht.

6. Verfahren nach Anspruch 5, wobei jedes Frequenzband eine Bandbreite von 80 MHz hat.

7. Verfahren nach Anspruch 6, wobei eine Anzahl der Vielzahl von Frequenz-Unterblöcken zwei ist.

8. Verfahren nach Anspruch 1, wobei die codierten Blöcke durch Verwenden eines Round-Robin-Schemas geparst werden, um die Vielzahl von Frequenz-Unterblöcken zu erzeugen.

9. Sender (1000) zum Senden eines Datenblocks in einem drahtlosen Kommunikationssystem, umfassend:

eine Codiereinheit (1010), die konfiguriert ist, um eine Anzahl von Bits, die einer einzelnen Achse einer Signalkonstellation s zugeteilt sind, und eine Anzahl von Codierern N_ES zu bestimmen und codierte Informationsbits zu codieren und zu parsen, um einen codierten Block von N_CBPSS Bits pro räumlichem Strom zu erzeugen;

eine Parsingeinheit (1020), die konfiguriert ist, um den codierten Block zu parsen, um eine Vielzahl von Frequenz-Unterblöcken zu erzeugen, basierend auf s und N_ES; und

eine Sendeeinheit (1030), die konfiguriert ist, um jeden von zwei Frequenz-Unterblöcken durch Verwenden eines Interleavers mit einer Größe entsprechend einer Bandbreite eines Frequenzbands entsprechend einem der Vielzahl von Frequenz-Unterblöcken unabhängig einem Interleaving zu unterziehen und die Vielzahl von einem Interleaving unterzogenen Frequenz-Unterblöcken zu einem Empfänger zu senden.

10. Sender nach Anspruch 9, wobei

gilt, wobei N_BPSCS die Anzahl von codierten Bits pro Hilfsträger pro räumlichem Strom ist.

11. Sender nach Anspruch 10, wobei die Codiereinheit konfiguriert ist, um die Informationsbits durch folgendes zu codieren:

Codieren der Informationsbits durch Verwenden von N_ES Vorwärtsfehlerkorrektur-(FEC-)Codierern; und

neu Anordnen der codierten Informationsbits, um den codierten Block von N_CBPSS Bits zu erzeugen, basierend auf s.

12. Sender nach Anspruch 10, wobei die Signalkonstellation für wenigstens eines von binärer Phasenumtastung (BPSK), Quadraturphasenumtastung.(QPSK), 16-Quadraturamplitudenmodulation (QAM), 64-QAM und 256-QAM verwendet wird.

13. Sender nach Anspruch 10, wobei die Vielzahl von Frequenz-Unterblöcken jeweils einer Vielzahl von Frequenzbändern entspricht.

14. Sender nach Anspruch 13, wobei jedes Frequenzband eine Bandbreite von 80 MHz hat.

15. Sender nach Anspruch 14, wobei eine Anzahl der Vielzahl von Frequenz-Unterblöcken zwei ist.

Revendications

1. Procédé de transmission d'un bloc de données dans un système de communication sans fil, comprenant les étapes suivantes :

déterminer un nombre de bits attribués à un seul axe de constellation de signal, s, et un nombre de codeurs, NES ;

coder et analyser des bits d'information pour former (S910) un bloc codé de N_CBPSS bits par flux spatial ;

analyser le bloc codé pour former une pluralité de sous-blocs de fréquence sur la base de s (S940) et de N_ES (S920) ;

entrelacer chacun de deux sous-blocs de fréquence de façon indépendante, à l'aide d'un entrelaceur ayant une taille correspondant à une largeur de bande d'une bande de fréquences correspondant à un sous-bloc de la pluralité de sous-blocs de fréquence (S950) ; et

transmettre (S950) la pluralité de sous-blocs entrelacés à un récepteur.

2. Procédé selon la revendication 1, dans lequel

où N_BPSCS représente le nombre de bits codés par sous-porteuse par flux spatial.

3. Procédé selon la revendication 2, dans lequel l'étape de codage des bits d'information comprend les étapes suivantes :

coder les bits d'information à l'aide de N_ES codeurs à correction d'erreur directe (FEC) ; et

réorganiser les bits d'information codés pour former le bloc codé de N_CBPSS bits sur la base de s.

4. Procédé selon la revendication 2, dans lequel la constellation de signal est utilisée pour au moins une modulation parmi la modulation par déplacement de phase bivalente (BPSK), la modulation par quadrature de phase (QPSK), la modulation d'amplitude en quadrature à 16 états (QAM), la QAM-64 et la QAM-256.

5. Procédé selon la revendication 2, dans lequel la pluralité de sous-blocs de fréquence correspond respectivement à une pluralité de bandes de fréquences.

6. Procédé selon la revendication 5, dans lequel chaque bande de fréquences a une largeur de bande de 80 MHz.

7. Procédé selon la revendication 6, dans lequel les sous-blocs de la pluralité de sous-blocs de fréquence sont au nombre de deux.

8. Procédé selon la revendication 1, dans lequel le bloc codé est analysé à l'aide d'un système à permutation circulaire pour former la pluralité de sous-blocs de fréquence.

9. Émetteur (1000) de transmission d'un bloc de données dans un système de communication sans fil, comprenant :

une unité de codage (1010) configurée pour déterminer un nombre de bits attribués à un seul axe de constellation de signal, s, et un nombre de codeurs, N_ES, et pour coder et analyser des bits d'information afin de former un bloc codé de N_CBPSS bits par flux spatial ;

une unité d'analyse (1020) configurée pour analyser le bloc codé afin de former une pluralité de sous-blocs de fréquence, sur la base de s et de N_ES ; et

une unité de transmission (1030) configurée pour entrelacer chacun de deux sous-blocs de fréquence de façon indépendante, à l'aide d'un entrelaceur ayant une taille correspondant à une largeur de bande d'une bande de fréquences correspondant à un sous-bloc de la pluralité de sous-blocs de fréquence et pour transmettre la pluralité de sous-blocs de fréquence entrelacés à un récepteur.

10. Émetteur selon la revendication 9, dans lequel

où N_BPSCS représente le nombre de bits codés par sous-porteuse par flux spatial.

11. Émetteur selon la revendication 10, dans lequel l'unité de codage est configurée pour coder les bits d'information :

en codant les bits d'information à l'aide de N_ES codeurs à correction d'erreur directe (FEC) ; et

en réorganisant les bits d'information codés pour former le bloc codé de N_CBPSS bits sur la base de s.

12. Émetteur selon la revendication 10, dans lequel la constellation de signal est utilisée pour au moins une modulation parmi la modulation par déplacement de phase bivalente (BPSK), la modulation par quadrature de phase (QPSK), la modulation d'amplitude en quadrature à 16 états (QAM), la QAM-64 et la QAM-256.

13. Émetteur selon la revendication 10, dans lequel la pluralité de sous-blocs de fréquence correspond respectivement à une pluralité de bandes de fréquences.

14. Émetteur selon la revendication 13, dans lequel chaque bande de fréquences a une largeur de bande de 80 MHz.

15. Émetteur selon la revendication 14, dans lequel les sous-blocs de la pluralité de sous-blocs de fréquence sont au nombre de deux.

Drawing